Global Patent Index - EP 3742134 A1

EP 3742134 A1 20201125 - CIRCUIT AND METHOD FOR RATIOMETRIC LIGHT CHANGE DETECTION

Title (en)

CIRCUIT AND METHOD FOR RATIOMETRIC LIGHT CHANGE DETECTION

Title (de)

SCHALTUNG UND VERFAHREN ZUR RATIOMETRISCHEN LICHTÄNDERUNGSERKENNUNG

Title (fr)

CIRCUIT ET PROCÉDÉ DE DÉTECTION DE CHANGEMENT DE LUMIÈRE RATIOMÉTRIQUE

Publication

EP 3742134 A1 20201125 (EN)

Application

EP 19176095 A 20190523

Priority

EP 19176095 A 20190523

Abstract (en)

A circuit (100) for detecting a ratiometric change in an incident light (126) intensity is provided, including an operation amplifier (110), a light sensor (120) connected to an inverting input (112) of the amplifier, a feedback loop (130) connecting an output (116) of the amplifier to the inverting input of the amplifier and including at least one circuit element (132) having a logarithmic voltage-current dependence, a high-pass filter (140) configured to filter a signal (V<sub>AMP</sub>) output from the amplifier to generate a high-pass filtered signal (V<sub>HPF</sub>), and a comparison element (150) configured to compare the high-pass filtered signal with at least a first threshold value and to output a signal (V<sub>OUT</sub>) which, as a response to an amplitude of the high-pass filtered signal passing the at least a first threshold value, changes to indicate a ratiometric change in the intensity of the incident light. A method of detecting a ratiometric change in an incident light intensity, a smart contact lens, a method of operating the smart contact lens and various uses of the circuit and/or method are also provided.

IPC 8 full level

G01J 1/44 (2006.01); G01J 1/42 (2006.01); G02C 7/04 (2006.01)

CPC (source: CN EP IL US)

G01J 1/44 (2013.01 - CN EP IL US); G02C 7/04 (2013.01 - CN EP IL US); G02C 7/046 (2013.01 - CN); G02C 7/047 (2013.01 - CN); G02C 7/101 (2013.01 - US); G02C 11/10 (2013.01 - CN EP IL); G02F 1/13312 (2021.01 - US); G02F 1/137 (2013.01 - US); G01J 2001/4242 (2013.01 - EP IL); G01J 2001/446 (2013.01 - CN EP IL US); G02F 2203/48 (2013.01 - US)

Citation (search report)

Designated contracting state (EPC)

AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

Designated extension state (EPC)

BA ME

DOCDB simple family (publication)

EP 3742134 A1 20201125; EP 3742134 B1 20231129; CA 3141497 A1 20201126; CN 114207509 A 20220318; DK 3742134 T3 20240212; EP 3973352 A1 20220330; ES 2973940 T3 20240625; IL 288257 A 20220101; JP 2022534054 A 20220727; JP 7480185 B2 20240509; US 11927479 B2 20240312; US 2022252450 A1 20220811; WO 2020234278 A1 20201126

DOCDB simple family (application)

EP 19176095 A 20190523; CA 3141497 A 20200519; CN 202080052627 A 20200519; DK 19176095 T 20190523; EP 2020063919 W 20200519; EP 20726821 A 20200519; ES 19176095 T 20190523; IL 28825721 A 20211121; JP 2021569483 A 20200519; US 202017613529 A 20200519